Electrical condenser



July 16, 1929. W, A. GRAHAM 1,721,152

ELECTRICAL CONDENSER Filed Dec. 2, 1920 avweulioz W/LZJAMA aim/Y @513elf/tuna A I Patented July 16, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM A. GRAHAM, OE BROOKLYN, NEW YORK, AssIeNoR T RADIO CORPORATIONOF AMERICA, A COR ORATIOR OF DELAWARE.

ELECTRICAL CONDENSER.

Application filed December 2, 1920. Serial No. 427,671.

This invention relates to electrical condensers and more particularly toa condenser of fixed capacity.

The Object of the invention is to secure a neat compact element and toprovide convenient supporting means for the plates and terminalarrangements for the unit.

In preparing my condenser unit I utilize a number of thin metallicstrips separated by a dielectric, and have thealternate strips of metalextend from opposite ends of the dielectric. The projecting ends areconnected after clamping the strips and the element is inserted in aninsulating tube to which air tight caps are applied which serve also asthe condenser terminals.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims.

The invention itself, however, both as to its organization andadvantages thereof, will best be understood by reference to thefollowing description taken in connection with the accompanying drawingin which Fig. 1 is an enlarged longitudinalsection of the condenser.

Fig. 2 is a perspective view of a detail.

Fig. 3 is a transverse section on the line AA of Fig. 1.

Fig. 4: is a view partially in section showing a method of connectingthe condenser in circuit.

The condenser plates preferably consist of a number of strips of thincopper or other suitable metal such as tin foil. A. flexible metalsheath 1 which is preferably channel shaped is utilized in assemblingthe unit. Thin sheet mica strips 2 are fitted at the sides of thechannel and a strip of dielectric consisting also of thin sheet mica 3is fitted in the bottom. The plates consists of alternate metal strips4, 5 fitted in the channel with mica strips 6 for a dielectric betweeneach of the strips. The mica strips 6 are approximately the same lengthas the sheath. The metal strip 3 have projections 7 extending beyond themica strips at the left and the projections 8 of the strips project fromthe right. When sufficient strips have been as sembled pressure isapplied to force them together and the sides of the channel 1 are bentover the top of the unit to hold the elements rigidly together.

The unit is then placed in a drying oven and heated for a suitable timeat a suitable temperature to remove all the moisture and'is then dippedin boiling condenser Wax and allowed to cool.

The terminals of the corresponding plates are connected together in anysuitable manner preferably by pressing them tightly together andsoldering or tinning.

To prevent access of moisture as Well as to protect the unit and providea convenient container, the unit is inserted in a glass tube 9. Metalcaps 10, 11 of brass, for example, serve as closures for the glass tubeand as terminals. Connection between the caps and the plates isconveniently made by first filling one of the capswith a low meltingmetal 12 such as .Voods metal which is preferably formed of four partsbismuth, two parts lead, one part tin, one part cadmium and melts atapproximately Centigrade and has the property of. expanding upon coolingand solidifying and then fitting the glass tube in the cap and'dippingthe tinned end inthe molten metal and allowing to cool. When the metalhas hardenedthe other cap will be fitted to the other end of the glasstube in a similar manner. Bythis means a firm support, convenientterminals and anair tight closure are provided for the element. In Fig.4 I have shown a pair of spring metal clips 13, 14c fastened to aninsulating base for conveniently supporting and making electricalconnection to the end caps which constitute the terminals. The clips areprovided with circular openings 15 adapted to receive the pointed endsof the caps.

Condensers constructed as described may be made in various sizes, butthe construction is particularly well adapted for small fixed condensersused inradio receiving apparatus. 95 I -laving described my invention,what I claim is 1. As an article of manufacture, an electric reactancehaving conducting members projecting alternately from opposite ends 100thereof, and having the ends of said conducting members embedded in amass of fusible metal and said masses of metal forming the sole supportfor said reactance.

2. As an article of manufacture, anelec- 5 tric reactance havingconducting members projecting alternately from each end thereof, saidreactance being enclosed within a tube of insulating material, and theends of said tube and said conducting material being em- 1 nally andspaced apart by layers of dielectric bedded in a mass of metal in amanner to support and maintainsaid reactance out of con tact with saidtube.

3. As an article of manufacture, an electric reactance having conductingmembers extending alternately from each. end thereof, said reactancebeing enclosed Within a tube of insulating material andthe-ends of saidtube and of said conducting material being embedded in a mass of metalin a manner to form an airtight closure for said tube and to maintainand support said react'ance out of contact therewith.

4. As an article of manufacture, an electric condenser comprising aplurality of interleavedmetallic strips extending longitudinally andspaced apart by layers of dielectric material, the alternate metallicstrips having ends projecting on opposite sides beyond the dielectricand said strips being closely embraced by a sheath of clamping materialto form a condenser unit and said condenser unit having the projectingends embedded in a massof metal in a manner to support the same solelyby said strips.

5. An electric condenser comprising a plurality of interleaved metallicstrips extending longitudinally and spaced apart by layers of dielectricmaterial, the alternate metallic strips having ends projecting onopposite sidesbeyond the dielectric, and having said ends embedded in aconducting cap containing a mass of metal.

6. An electric condenser comprising a con denser unit made up of aplurality of interleaved metallic strips extending longitudiand saidmaterial forming the'sole supportfor said interleaved metallic strips.

8. An electric condensercomprising an insulating tube, a plurality ofinterleaved metallic strips therein extending longitudinally andspacedapart by layers of dielectric material,. the alternate metallicstrips having ends projecting on opposite sides beyond the dielectric,and a fusible metalplug in each end of said tube securing and contactingwith said ends.

9. As an article of manufacture, an electrlc condenser comprising anenclosing tube,

a plurality of interleaved metallic strips ofrelatively great length ascompared to width, disposed therein extending longitudinally and spacedapart by layers of dielectric material and provided with substantiallyconical conducting members at each end for supporting said condenser andsimultaneously making electrical contact therewith.

10. In combination, a condenser whose greatest transverse. dimension issmall compared with the length thereof having a pair of pointed terminalmembers disposed at opposite ends thereof, a base, a pair of springclips extending from said base, prongs pro jecting from the clips andimbedded in the base, said clips being arranged in a manner to supportand make contact with said condenser when inserted therebetween.

ll In combination, a condenser Whose greatest transverse dimension isrelatively small as compared with. its length and having a pairofcpointed terminals at the ends thereof. a base, and resilientconducting means provided with projecting prongs imbedded in the base,said means adapted to support and make electrical contact with saidcondenser.

12.1n combination, a condenser whose greatest transverse dimension isrelatively metallic strips having ends projecting on opposite sidesbeyond the dielectric and the adjacent ends being pressed together toform contact members at the opposite ends of the tube, and a pair ofterminals at opposite ends of the tube electrically and mechanicallyconnected to the contact members and forming the sole support for saidinterleaved strips and dielectric material.

14. An electrical condenser comprising an enclosing tube of insulatingmaterial, a plurality of interleaved relativel narrow metallic stripstherein extending longitudinally and spaced apart by layers ofdielectric material, the alternate metallic strips having endsprojecting on oppposite sides beyond the dielectric and the fidJfiCGIltmembers being pressed together to form contact members at the oppositeends of the tube, a pair of sub stant-ially air tight metallic closuresfitted to the ends of the insulating tube and electrically andmechanically connected to the contacts and forming the sole support forsaid interleaved strips and dielectric material.

15. An electric condenser comprising an enclosing tube, a plurality ofinterleaved relatively narrow metallic strips therein extendinglongitudinally and spaced apart by layers of dielectric material, thealternate metallic strips having ends projecting beyond the dielectrictowards the opposite ends of the tube, a pair of conducting caps fittedon the ends of the tube and a filling of metallic conducting material insaid caps surrounding the projecting ends of the strips and forming thesole mechanical support for said strips. I

16. An electrical condenser comprising'an air tight tube of insulatingmaterial, a plurality of interleaved relatively narrow metallic stripstherein extending longitudinally and spaced apart by layers ofdielectric material, the alternate metallic strips having endsprojecting'beyond the dielectric toward the opposite ends of the tube,means for clamping the metallic strips and dielectric together, a pairof metallic caps fitted over the ends of the tube and an air tightfilling of metallic conducting material in said caps and the ends of thetube surrounding the projecting ends of the strips and formingthe solemechanical support for said strips.

17. An electrical condenser comprising an enclosing tube of insulatingmaterial, a plurality of relatively narrow interleaved metallic stripstherein extending longitudinally and spaced apart by layers ofdielectric material, the alternate metallic strips having endsprojecting on opposite sides beyond the dielectric and the adjacentmembers being pressed togetherto form contact members at the oppositeends of the tube, a metallic clamping sheath around the strips anddielectric, a pair of air tight metallic closures for the ends of thecaslng electrically conductin tric reactance, provided with alternatelyextending conducting members, an insulated container for said reactanceand means expanded against the wall of said container for supportingsaid reactance at spaced intervals in said container. i

19. As an article of manufacture, an electric reactance, a glass tubeand a pair, of expanded metal plugs of low fusing material supportingsaid reactance at spaced intervals in saidcontainer, and forming an airtight seal with said glass tube for protecting said reactance 20. Anelectric condenser, comprising an enclosing container, a plurality ofinterleaved metalic strips extending longitudinally and spaced apart bylayers of dielectric material,

the alternate metallic strips extending on op-4 posite sides beyond thedielectric and being integrally united with supporting and COIL- ingsaid ends,

W. A. GRAHAM.

members, and conducting caps at

